The government charts are, if you use ENC or Raster from the government. But these private charts are enhanced, and it takes labor and engineering to make that work, and it takes marketing to make it a business. Also the programs need to be developed, enhanced and kept up to date.

Navionics adds a really slick auto-route feature, and crowd-sourced depth overlays using data from user's CPs. When you consider how old the source charts and government surveys are, that's very valuable. Garmin adds interactive radar displays and waypoint/route sharing to your Garmin CP, which is proprietary but a big value-add for Garmin owners.

I don't object to licensing fees if they're reasonable.